The apartment blocks are going up so quickly around the outskirts of the West Bank city of Ramallah that the place seems momentarily to grow before your eyes. It makes it ever more difficult for the Palestinian lawyer Raja Shehadeh to find the original starting points for the walks he has been taking for the past quarter of a century into the Ramallah hills and beyond.

Caught between the city and the flourishing of Jewish settlements here and across the rest of the occupied West Bank is a sweeping range of hills and narrow valleys that are increasingly out of bounds to Palestinians. It is what Shehadeh calls a "vanishing landscape".

One recent afternoon Shehadeh, who founded the human rights organisation Al-Haq, stood on a vantage point on the western edge of the city, an area that was olive groves a few years ago. A short neat man, he was dressed in a short-sleeved shirt and wore laced-up, soft leather walking shoes, which were planted in the dirt next to piles of rubble and discarded car tyres. Below him, he found a path, stretching down through the valley, that he had walked many times in previous years. It ran past terracing and olive trees, beyond a series of partially hidden, circular stone shelters built years ago by shepherds and on across a lush spring. The folds in the land he describes as "not unlike that of a gigantic walnut". But now there are new additions to the landscape: not just the housing projects but also, carving awkwardly across the valley, a road reserved for Israeli military patrols and then further off, on a hilltop, a Jewish settlement established after Shehadeh first began his walks. "I avoid coming here. It's too sad," he said.

Shehadeh's family lived in the port city of Jaffa until 1948 when, during the war that brought the creation of the state of Israel, they fled to Ramallah, expecting soon to return. They never did and their longing for the city dominated his childhood. His father, Aziz Shehadeh, was a successful lawyer who after the 1967 war advocated a two-state solution for Israelis and Palestinians. It was not a popular position among Palestinians at the time and in 1985 he was stabbed to death, probably by someone angered by one of his legal cases, although the assailant was never found. Shehadeh tried to track down the killer, and explained how he almost succeeded in his memoir Strangers in the House.

Shehadeh had followed his father into law knowing that he really wanted to write. "I suppose I had the romantic idea, which I still have, that writing should be about the stuff of life. You deal with things and then you make something out of them, but you must be able to touch them and feel them and experience them," he said. He worked as a human rights lawyer six days a week, including fighting settlers' land claims, and writing early in the mornings, at night and on Saturdays. While his legal work is mostly in Arabic, it came naturally for him to write in English, the language of his schooling.

In another memoir, When the Bulbul Stopped Singing, adapted for the stage in Edinburgh and the US, he described life in Ramallah during an Israeli military operation and complained that the Palestinian story had been turned into a "soap opera" by outsiders. "Everyone felt they knew what was good for me and no one thought of asking," he wrote.

Today Shehadeh, who has kept a private journal for 40 years, has become one of the most prominent diarists of modern Palestinian life. His latest book describes six walks through the West Bank and charts the expansion of Israel's settlements, all illegal under international law. Many are built on hilltops, securing water supplies, often linked by their own networks of roads and overlooking villages in the valleys beneath. He writes: "As our Palestinian world shrinks, that of the Israelis expands, with more settlements being built, destroying forever the wadis and cliffs, flattening hills and transforming the precious land which many Palestinians will never know."

He notes the travel restrictions imposed on Palestinians since the early 1990s, the time of a peace agreement many hoped would herald a Palestinian state. In 1991 he worked as a legal expert for the Palestinian negotiators but he is bitter about the Oslo deal of 1993, which he dismisses as "nothing but a surrender document, a false promise for a better future". Since then he has become increasingly frustrated and disillusioned. "I was continuing to moan about Oslo, Oslo and it was getting very tiring," he said. "So I wanted to put it all out, express what most people do not know really, even people here, and make my way out emotionally." Writing, more than anything else, has helped him overcome the anger that he says "burns in the heart of most Palestinians".

Of armed groups and suicide bombers, Shehadeh has little to say. Palestinian violence, he notes, has simply allowed Israel to argue more convincingly that it is constantly at war. But his books offer an important counterpoint to the dominant Middle Eastern narrative that portrays an unruly Palestinian population overwhelmed terrorists.

Most striking is his deep fear of being forced off the land. "I was actually obsessed, especially when I was working on the book, feeling that it's all lost, that the land is lost," he said. "I was feeling that I must somehow represent this and bring this out and show what a great loss it is." But he also acknowledges an uncomfortable truth rarely heard in Palestinian circles: that Israel's settlers are often as deeply attached to the West Bank as the Palestinians. In his book he describes how on one walk he encountered a settler and, astonished to find him equally in love with the land, confronted him over the politics of the conflict as they shared a water-pipe on the hillside. He writes: "Despite the myths that make up his world-view, how could I claim that my love of these hills cancels out his? And what would this recognition mean to both our future and that of our respective countries?"

He is critical of the Palestinian leadership, arguing that a two-state peace agreement is remote and another round of conflict ever more likely. "No country will give up land without pressure, I mean why should they? It's not that they will suddenly see the light and so it's a recipe for more war," he said.

As in his earlier books, he writes often about sumoud, which means perseverance or steadfastness. It is, in effect, his non-violent struggle against the occupation, the idea that simply staying put has a political role. He was asked to write an essay for a human rights group earlier this year about the 40th anniversary of the 1967 war and of Israel's occupation. "I thought of so many things and then I realised two constants. One, settlements have never stopped. The second thing is that we have stayed," he said. "It is ultimately a struggle to get us out of our land and staying is the most important thing. By staying we achieve something and certainly deny the other side total victory."

Picnic at Wadi Qelt

The canyon was deep and narrow. The large boulder walls twisted and curved, forming small basins. We walked along the narrow path until we reached a wider part of the valley, which was sheltered on both sides by very high cliffs. Below, the water was thick with reeds and spearmint. We found a spot by a large carob tree and had our picnic. The water streamed below where we sat.

Then we heard noises. We looked up and, below the escarpment at the opposite side of the stream, saw a number of settlers approaching. They must have seen us as trespassers, potentially dangerous but perhaps, by the way we looked sitting there drinking coffee and eating our salads, not quite people on a military mission. One of the girls from the group approached Rema and asked her: "Where are you from?" Rema's answer was both straightforward and correct. She simply said: "From here."

The settler women wore long skirts and covered their hair. They continued walking on the narrow paths along the steep rock opposite us while we held our ground by the carob tree and tried to avoid looking at them. An uneasy sharing of the picnic ground proceeded, with each side excelling in keeping watch without seeming to do so.

Just as we were leaving I looked up the rock wall below which we had been sitting and saw a young woman with the long orthodox dress and headscarf standing reverently. Her face was turned westward; she had a calm pious expression. She was praying. Oddly, it was a flattering sight: here was someone who appreciated my land so much that she was inspired to give thanks to her God in prayer. And yet I could not help being suspicious of her motives. What was the nature of her supplication?

· Extracted from Palestinian Walks by Raja Shehadeh, published by Profile Books this week at £9.99